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the dualtower

Dualtower is an inventive concept of a tower for wind turbines . It combines a new method of building a tower structure with the possibility to store hydrogen gas in the tanks (vessels) of the tower structure.

We can do this through the use of CPV’s -Constructive Pressure Vessels- for the tower structure.

Dualtower can help the world to produce sufficient green hydrogen. The future demand for green hydrogen will increase dramatically if steel producers, chemical industry, ocean and air transport will required CO2 neutral fuels for their business model.

wind engine
a new look on
wind energy
a new way to
store energy
producing huge
amounts of green
a new feature in
wind power
Dualtower’s are preferably installed onshore, due to their simple design and multi-leg assembly, they can be installed in nearly every location, from rock to sand. Offshore also could be possible, but due to the higher installation cost, this is not our first goal.

The new features are:
  • pressure vessels to store single gas or single liquids (e.g. liquified NH3)
  • when equipped with dCPV, able to store N2 and H2 to produce NH3
  • cluster concept instead of huge electrolyzers parks, running autonomously and remotely controlled
  • harvest remote wind energy and bring it to the economical area’s
  • clever building concept allowing installment even in remote area’s without the need for huge cranes (ask us and we show you how)
Efficient would be for example Greenland, Chili, Argentina, Morocco, Alaska, New Zealand but also the inland regions as Kazakhstan or the Mid-West of the USA.

Moreover, installing a few Dualtower also can be advantageous for wind parks since it offers energy balancing function (store excess of energy and make it available when there is a shortage) and thus will increase the yield of the wind park as a whole.
conceptional fact sheet pdf
Please download here the conceptional fact sheet for a 100 meter tower.
duplex CPV
The evolution of the CPV is the dCPV. duplex Constructive Pressure Vessel.
  • the inner segment contains the hydrogen gas.
  • the outer segment contains nitrogen gas.
This way, we have solved the remarks that came up when we disclosed that we are going to store hydrogen gas in a tower structure.
Issues with steel embrittlement, sealing and gas permeation were resolved with the dCPV assembly.
The inner vessel containing the hydrogen gas, is a fully welded stainless steel tube, with a rather thin wall. If the hydrogen permeates through the stainless steel wall, it will come into the inert nitrogen gas layer.
Why can we use a thin wall for the inner vessel?
If we balance the pressure of the N2 and H2 in the same pressure range, the pressure difference (ca 5 to 10 bar dP) will be small, so a thin wall is sufficient.
It is the outer wall (in contact with N2) that takes all the mechanical loads of the working pressure and weights.
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producing green ammonia
(zero CO2 emission)
Locations with maximum wind occurrence increase the capacity factors drastically and thus are the better investment. If the wind turbine is operating at for example a capacity factor of 32% instead of 24% this is a huge difference. With onshore clusters of Dualtowers, we can achieve this. We harvest the wind, converted instantly to hydrogen gas using electrolyzers.
The efficiency of a high capacity factor can be gone if the transport of the energy is not efficient. There are different routes to transport hydrogen, using pipelines, liquified hydrogen, LOHC (liquid organic hydrogen carriers molecules), conversions to Methanol (but than an CO2 source needs to be available close to the wind location).

Our conclusion is that Ammonia is the most simple, most reliable and best known technology, to store hydrogen over a long period of time in an efficient way. The Ammonia synthesis is one of the oldest chemical reactions, the Haber–Bosch process. Ammonia is a base chemical produced at industrial scale, currently about 180 million tons per year.

Ammonia in a liquid state (-33°C) is easier and hugely more efficient to transport than hydrogen gas or even liquified hydrogen.
solar ammonia
solar ammonia
The DualSolar concept is similar to the Dualtower, except that we have solved the issues related to the day/night cycle.

In the DualSolar concept, the photovoltaic panels will capture the sunlight, convert it into electrical energy, that is used by Hydrolyzers to produce Hydrogen gas (H2). We store the H2 in the dCPV's, the inner tube contains the Hydrogen gas (H2) and is a fully welded construction, whereas the outer tube segment contains the Nitrogen gas (N2). So a simple, safe, and economical design.
The operating pressure of the DualSolar dCPV can go up to 200 bar, resulting in 3 to 6 full-day equivalents of H2/N2 production. So sufficient buffer, even if the sunlight would disappear for a few days.

Connected with the DualSolar dCPV is an Ammonia synthesis (NH3), due to the buffering of the hydrogen/nitrogen gas, the Ammonia production can run 24/7, 365 days, which is a massive benefit for the total efficiency. Truly green solar ammonia!
conceptional fact sheet pdf
Please download here the conceptional fact sheet for DualSolar.
green energy comparison
A. Is it efficient to use precious agricultural land to produce biofuels? Wouldn't it be smarter to install PV-panels or a Dualtower in non-agricultural area's (e.g., desert, mountains) and use the agricultural land for food production?
We have compared the yields (1-year production) of:
  • 1 ha of various biofuel crops
  • 1 ha of photovoltaic cells (considering 10h of production per day)
  • 1 wind turbine type Dualtower (using one electrolyzer (1.5MW), counting 200 days of 365 days production)

B. Energy stored as chemical energy has a drastically higher density than any batteries.
comparison one
Please have a look at the graph about annual yield.

comparison two
Please have a look at the graph about energy storage capacity.
frequently asked
Can we place orders for Dualtowers?
Unfortunately, no. We are still in concept stage, working hard to bring it to prototyping. If all works well we expect to install the first Dualtower in 2023.
Where are locations with optimum wind occurrence?
Chili, Argentina, West-coast Australia, New Zealand, Morocco, Somalia, Namibia, South-Africa, Norway, Ireland, Greenland, Iceland, Japan, Taiwan
Can we invest in Dualtowers?
Yes, in the future we will present a detailed plan to potential investors, if they do not participate, we will consider crowdfunding.
The idea seems to be so simple, will it work?
Yes, we are convinced it works. We are using standard and proven materials; wind towers can be mechanically engineered. Granted patents proof the innovative features of our idea.
For electrolysers, you need fresh water, from where will you get it?
Some of the countries we have listed have sufficient water resources. In a country poor of water, we can use sea water and desalinate it, the energy consumption for this is only 5-6 kWh per 1m3
Is ammonia not dangerous?
While every chemical carries an inherent risk, ammonia is one of the oldest chemicals that have been produced on a commercial scale. Guidelines have been set for handling ammonia, making it as safe to handle as any other chemical. Infrastructure for transport, handling and storing on a large scale has already been built. With its pungent smell, ammonia is also “self-alarming”; as soon as there is a leak, the strong smell will alert anyone nearby. Concentration levels when detectable by smell are below the level to cause harm.
Why are you not shipping the hydrogen as liquid (cryogenic) hydrogen?
It would take 10 times the amount of energy to liquify hydrogen as opposed to converting it to ammonia. The temperature needed to keep hydrogen liquid is also far lower (-252°C) than it is to keep ammonia liquid (-33°C), thus increasing storage costs for liquid hydrogen vs. liquid ammonia. Furthermore, by weight there is more hydrogen present in 1 liter of liquid ammonia, then is present in 1 liter of liquid hydrogen.
How long can you store ammonia?
Ammonia is generally stored as a liquid, either at a low temperature or increased pressure or a combination of both. As long as the temperature and/or pressure is maintained, ammonia could be stored indefinitely.
Can ammonia be converted back to hydrogen?
Yes, ammonia, a hydrogen carrier, can be cracked to release the hydrogen kept within. Continuing research has lowered the temperature needed for decomposing ammonia back into nitrogen and hydrogen.
Can ammonia be used for energy purposes without converting it back to hydrogen?
Ammonia is flammable, albeit in very specific mixtures. Although the energy content is lower than that of fossil fuels, a diesel engine can be converted to use ammonia as a fuel. Furthermore, gaseous ammonia can be burnt in a gas turbine, similar to natural gas.
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